WASHINGTON — Thales Alenia Space said Jan. 10 it received a contract from the European Space Agency worth approximately 150 million euros ($172.4 million) to build the Fluorescent Explorer satellite.

Fluorescent Explorer, or FLEX, is an ESA Earth Explorer mission that will measure photosynthetic activity by mapping vegetation fluorescence.

The satellite is projected to launch in 2023 aboard a Vega C rocket, according to Thales Alenia Space. Raphael Berruyer, FLEX project manager at Thales Alenia Space, said by email that FLEX has a lifespan of five years, and is projected to weigh 450 kilograms.

When ESA selected the FLEX mission in 2015, it expected the satellite to launch in 2022, a year sooner than the current schedule. Berruyer said the mission schedule was extended to accommodate requested performance improvements to the satellite’s main instrument: the Fluorescence Imaging Spectrometer, or FLORIS.

ESA awarded the FLORIS contract to Rome-based Leonardo in 2016. Under a contract change announced Jan. 10, Thales Alenia Space, not ESA, is now Leonardo’s customer for the instrument.

FLEX will operate in an 815-kilometer sun-synchronous orbit in tandem with one of the European Commission’s Sentinel-3 satellites. Data from FLEX’s spectrometer and Sentinel-3’s optical and thermal sensors when combined will “provide an integrated package of measurements to assess plant health,” Thales Alenia Space said.

In a statement, Marc Henri Serre, Thales Alenia Space head of observation and science, said winning the FLEX contract demonstrated the success of submitting a full industry consortium early in a program.

“This contract is the culmination of Thales Alenia Space’s development strategy in Europe,” he said.

Berruyer said that while subcontractor selection typically occurred six months to two years into past ESA programs, Thales Alenia Space selected FLEX subcontractors at the beginning.

“[A]ll the supply chain has been fully selected by TAS in the frame of the bid, [and] no new selection phase is foreseen during program phase,” he said. [A]ll the supply chain can be kicked-off right after T0.”

Thales Alenia Space’s main outside suppliers for FLEX are Leonardo for FLORIS, and Ruag for platform design and production. Thales Alenia Space’s Spanish division will provide the radio-frequency subsystem, and Thales Alenia Space in the U.K. is leading satellite propulsion, as well as assembly, integration and testing.